Improve metadata, add link to Github repository

This PR improves the metadata of the model.

Would be great to update the other model cards too :)

README.md

@@ -1,5 +1,10 @@
 ---
 license: apache-2.0
+pipeline_text: text-generation
+library_name: transformers
+base_model: mistralai/Mistral-7B-Instruct-v0.2
 ---
 
-Model trained to accept and resist persuasion as appropriate, introduced by Stengel-Eskin et al. (2024): arxiv.org/abs/2410.14596 
+Model trained to accept and resist persuasion as appropriate, introduced by Stengel-Eskin et al. (2024): arxiv.org/abs/2410.14596 
+
+Github repository: https://github.com/esteng/persuasion_balanced_training